JPH086572Y2 - Vehicle height adjustment device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION << Industrial Application Field >> The present invention is a vehicle height adjusting device capable of increasing or decreasing the vehicle height by controlling a vehicle height adjusting actuator interposed between a vehicle body and wheels. Regarding

<< Prior Art >> As a prior art of the vehicle height adjusting device, for example, the applicant has previously filed Japanese Patent Application No. 59-165082 (Japanese Utility Model Publication No.
No.) proposed.

The device includes vehicle height adjusting actuators capable of increasing and decreasing the vehicle height between the vehicle body and the left and right wheels disposed on the front wheel side or the rear wheel side in the vehicle left-right direction. In the vehicle, the same number of vehicle height detectors as the vehicle height adjustment actuators, which outputs a vehicle height detection signal corresponding to the vehicle height of the portion based on the operation of the vehicle height adjustment actuator, and a control signal to the vehicle height adjustment actuator. And a controller for controlling each of the vehicle heights of the plurality of vehicle height detectors, wherein the controller continuously detects the value of each of the plurality of vehicle height detectors in a predetermined appropriate vehicle height region for a predetermined time or more. Vehicle height abnormality determining means for determining whether or not the vehicle height is exceeded, and when the vehicle height adjusting actuator has an abnormal vehicle height based on the determination result of this vehicle height abnormality determining means It is characterized by having a drive control means for controlling the vehicle height of the other vehicle height adjustment actuator to output the control signal so as to eliminate the vehicle height difference between the left and right sides, and thereby, the vehicle height adjustment actuator of the vehicle height adjustment actuator. By preventing a sudden change in the vehicle height difference in the left and right direction of the vehicle due to a failure or getting on or off the passenger, the vehicle is improved in maneuverability / stability and riding comfort.

By the way, in a general vehicle, when the brake pedal is depressed to activate the foot brake, braking force is generated on all wheels, but when the brake lever is pulled to activate the parking brake, braking force is generated only on the rear wheels. Has been done. For this reason, if the vehicle is moved from a flat road running state shown in FIG. 7 (a) to a hill running state and stopped midway, both when the foot brake and the parking brake are operated, the foot brake is released and only the parking brake is applied. When the vehicle is actuated, the vehicle attitude changes and the vehicle height fluctuates. Therefore, the control for correcting the vehicle height change is executed, and the vehicle body floor surface is controlled to be substantially parallel to the slope of the slope as shown in FIG.

<Problems to be solved by the invention> However, in the above-mentioned prior art, the actual vehicle height detected by the vehicle height detector is continuously set to a value in a predetermined predetermined proper vehicle height region for a predetermined time or more. When the vehicle is over the vehicle, the exhaust valve, the intake valve, and the intake / exhaust valve that are interposed between the fluid chamber and the fluid pressure source are opened to adjust the vehicle height. In this case, vehicle height adjustment is performed due to the vehicle height difference that occurs irrespective of changes in the loading load of people or luggage in the state in which the foot brake is activated and in the state in which it is released and only the parking brake is activated. As a result, a new target vehicle height is set based on the state where the vehicle body is tilted. Therefore, when the vehicle shifts from the above state to running on a flat road, the target vehicle height at that time is the state in which the vehicle body is tilted. Therefore, as shown in FIG. As a result, the vehicle height adjustment was performed again, and the frequency of vehicle height adjustment was increasing. Therefore, it is necessary to increase the durability of the vehicle height adjustment actuator, etc. according to the frequency of vehicle height adjustment, which will not only increase the cost to provide durability, but also increase the vehicle attitude due to wasteful vehicle height adjustment. There was an unsolved point that the passengers felt uncomfortable and anxious due to the change.

<< Means for Solving Problems >> The present invention was made by paying attention to such unsolved points of the prior art. As shown in the basic configuration diagram of FIG. A vehicle height adjusting actuator interposed between the vehicle height adjusting means, vehicle height adjusting means for driving the vehicle height adjusting actuator to adjust the vehicle height, and a vehicle speed detector outputting a detection signal according to the vehicle speed. And a vehicle height detector that outputs a detection signal according to the vehicle height, and a footbrake state detector that outputs a detection signal according to the operating state of the footbrake that applies braking force to all four front and rear wheels of the vehicle. , A parking brake state detector that outputs a detection signal according to the operating state of the parking brake that applies braking force to only one of the front and rear wheels of the vehicle, and a detection signal that corresponds to the open / closed state of the vehicle door or trunk Door / trunk condition check Output device, vehicle speed detector, vehicle height detector, foot brake state detector,
Based on the detection signals of the parking brake state detector and the door / trunk state detector, a drive command for adjusting the vehicle height by the vehicle height adjusting actuator is constantly output to the vehicle height adjusting means to close the door or the trunk. When the vehicle is stopped as it is, and only the foot brake is changed from the state in which both the foot brake and the parking brake are operating to the non-operating state, a command to prohibit the vehicle height adjustment by the vehicle height adjusting actuator is issued to the vehicle. And a control means for outputting to the high adjustment means.

<Operation> When the vehicle is running or stopped, the detection signals detected by the vehicle speed detector, the vehicle height detector, the foot brake state detector, the parking brake state detector, and the door / trunk state detector are used as control means. Is entered.

The vehicle height adjustment is performed by the vehicle height adjustment actuator that causes the actual vehicle height detected by the vehicle height detector to match the target vehicle height in the control means at all times except when the vehicle is stopped on a slope accompanied by the following changes in vehicle height. The drive command is output to the vehicle height adjusting means.

Therefore, during all times except when the vehicle is stopped on a slope accompanied by a change in vehicle height, changes in vehicle attitude such as rolls are suppressed by adjusting the vehicle height, and steering stability and comfortable riding comfort are secured.

On the other hand, when the vehicle is stopped on a slope accompanied by a change in vehicle height, the control means detects that the detection signals detected by the detectors are in a stopped state with the door or trunk closed and both the foot brake and the parking brake are activated. When only the foot brake is deactivated from the operating state, a command for prohibiting the vehicle height adjustment by the vehicle height adjustment actuator is output to the vehicle height adjusting means.

Therefore, when the vehicle is stopped on a slope accompanied by a change in vehicle height, prohibition of vehicle height adjustment prevents deterioration of riding comfort and anxiety, and improves durability reliability of the vehicle height adjustment actuator and vehicle height adjustment means. When the vehicle is stopped, operate the foot brake to stop the vehicle.If it is confirmed that the vehicle has stopped, operate the parking brake.If the foot brake only is deactivated from this state, the foot brake and parking brake When the braking force is applied to all four front and rear wheels by the operation, the braking force is applied to only one of the front and rear wheels by the operation of the parking brake only. The loss of the braking force that acts between the road surfaces and the slope of the stopped road surface move the center of gravity of the vehicle and the wheel load applied to the front and rear wheels fluctuates. The vehicle attitude changes. For example, when the foot brake is released from a state where both the foot brake and the parking brake are operated on an uphill road, the vehicle body center of gravity moves rearward and the vehicle body posture changes rearward and downward.

When the vehicle height adjustment control is executed when the vehicle is stopped on a slope accompanied by such a vehicle height change, the occupant in the stopped vehicle changes the vehicle body posture due to the change in the braking force state, and the vehicle height adjustment control thereafter. You will feel the change twice with the change in the body posture. Further, when the vehicle height adjustment control is executed when the vehicle is stopped on a slope, and when the vehicle then travels on a flat road, the vehicle height adjustment control is performed to restore the leaned vehicle body to the original posture by adjusting the vehicle height when the vehicle is stopped on a slope. As a result, the vehicle height adjustment frequency increases.

<< Embodiment >> The present invention will be described below with reference to illustrated embodiments.

2 to 6 are views showing an embodiment of the present invention.

First, the configuration will be described. As shown in FIG. 2, 1a is an air suspension device for the front left wheel, 1b is an air suspension device for the front right wheel, 1c is an air suspension device for the rear left wheel, 1d is an air suspension device for the right rear wheel, and these air suspension devices 1a-1d
Is composed of a shock absorber 2 and an air chamber 4 which is provided above the shock absorber 2 and which is defined by a rubber-like elastic body 3 such as rubber and which is a specific example of a vehicle height adjusting actuator. There is. The upper ends of the piston rod 5 and the rubber-like elastic body 3 of each shock absorber 2 are attached to the vehicle body 6, and the lower end of the shock absorber 2 is attached to an axle 7 rotatably supporting a wheel (not shown). The air suspension devices 1a to 1d are thus interposed between the vehicle body 6 and the wheels.

The air chamber 4 of each of the air suspension devices 1a to 1d stores an air conditioner press 9 which is a fluid pressure source through a communication hole 8 provided in a piston rod 5 and a high pressure air produced by the air conditioner press 9 The tank 10 is communicated with four sub-tanks 11a to 11d provided corresponding to the suspension devices 1a to 1d, and 10 open / close valves each including an electromagnetic switching valve are provided in the communication passages. 12a to 12j are arranged.

The contents of these 10 on-off valves 12a to 12j are as follows: the on-off valve 12a provided near the discharge port of the air conditioner press 9 is an exhaust valve, the on-off valve 12b provided at the outlet of the main tank 10 is an air supply valve, front wheels. The four open / close valves 12c, 12d, 12e, 12f provided at the respective branch parts on the side of the vehicle and the rear wheels are the supply / exhaust valves, the suspension devices 1a-1d, and the sub-tanks 11.
4 on-off valves 12 placed between a and 11d, respectively
g, 12h, 12i and 12j are spring constant changing valves.

The ten opening / closing valves 12a to 12j are each opened / closed by a control signal of a logical value "1" or a logical value "0" output from the controller 20 described later, and among them, the exhaust valve 12a and the air supply valve are included. 12b and 4 supply / exhaust valves 12c
By appropriately controlling the opening and closing of ~ 12f, high-pressure air from the air conditioner press 9 is supplied to the air chambers 4 of the respective suspension devices 1a-1d via the main tank 10, and the fluid in the air chambers 4 is thereby supplied. The vehicle height is continuously raised by increasing the pressure, and the vehicle height is continuously lowered by removing the air from the air chamber 4 to reduce the fluid pressure. Then, by controlling the opening and closing of the four spring constant changing valves 12g to 12j with the four supply and exhaust valves 12c to 12f closed, the volume of the air chamber 4 alone and the sub-tank 11
The volume is changed in two stages including the volume to which a to 11d are added, and thereby the air spring constants of large and small stages are obtained.

Therefore, in the air suspension devices 1a to 1d, while adjusting the vehicle height steplessly, the air spring constant at each vehicle height position can be changed in two steps of the normal position and the low position.

The air conditioner presser 9 (or the main tank 10 or both), the exhaust valve 12a, the air supply valve 12b, and the air supply / exhaust valves 12c to 12f constitute a vehicle height adjusting means, and the sub tanks 11a to 11d and the springs. Constant change valve 12g-12j
And constitutes the spring constant adjusting means.

In the figure, 13 is an air dryer for removing water from the air supplied to the air chamber 4, and 14 is a check valve for preventing the backflow of air from the main tank 10 to the air conditioner press 9.

Further, the controller 20 for controlling the opening and closing of the ten on-off valves 12a to 12j includes a vehicle speed detection signal DV according to the vehicle speed from the vehicle speed detector 15 and a vehicle height according to the vehicle height from the vehicle height detector 16. A detection signal DH, a foot brake detection signal DF from the foot brake state detector 17 according to the operating state of the foot brake, and a parking brake detection signal DS from the parking brake state detector 18 according to the operating state of the parking brake. ,door·
A door / trunk detection signal DD corresponding to the open / closed state of the door or the trunk is supplied from the trunk state detector 19.

The vehicle speed detector 15 is, for example, the vehicle speed detection signal according to the output side rotation speed of a transmission connected to an engine (not shown).
DV is output, and it is determined whether the vehicle is in a stopped state or in a running state depending on whether the vehicle speed detected based on the vehicle speed detection signal DV is zero. In addition, the vehicle height detector 16
Is configured by, for example, an ultrasonic distance measuring device that is attached to the lower surface of the vehicle body and outputs the vehicle height detection signal DH according to the height from the attachment position to the road surface. further,
The foot brake state detector 17 is constituted by, for example, a foot brake switch provided in the vicinity of the foot brake pedal, is turned on when the foot brake is depressed by a predetermined amount, and is turned off when the foot brake is released. A foot brake detection signal DF having a value "1" and a logical value "0" is output when the switch is off. Further, the parking brake state detector 18 is configured by, for example, a parking brake switch provided near the parking brake lever, and is turned on when the parking brake lever is pulled by a predetermined amount,
When it is returned, it turns off. For example, a parking brake detection signal with a logical value "1" when it is on and a logical value "0" when it is off.
Output DS. Furthermore, the door / trunk state detector 19 is composed of a switch that operates depending on whether the door or trunk is opened or closed. The switch is turned on when the door or trunk is closed and turned off when the door or trunk is opened. When it is off, the door / trunk detection signal DD with logical value "0" is output.

The controller 20 to which the detection signals of these detectors 15, 16, 17, 18, and 19 are supplied is an input / output port, an arithmetic processing unit (CO
U), a RAM, a storage device such as a ROM, and the like, and a microcomputer 21 having a storage device such as a vehicle speed detector 15 at its input port.
Vehicle speed detection signal DV, vehicle height detection signal DH of vehicle height detector 16 and foot brake detection signal DF of foot brake state detector 17
And parking brake condition detector 18 parking brake detector signal
The DS and the door / trunk detection signal DD of the door / trunk state detector 19 are supplied. Then, as shown in FIG. 3, based on the input signals DV, DH, DF, DS and its own output signal, the controller 20 outputs a logical value "0" from the output side port.
Alternatively, the control signal having the logical value “1” is set to the ten driving transistors 22.
Output to a to 22j according to the control state at that time.

The drive transistors 22a to 22j are individually connected to the electromagnetic solenoids 23a to 23j of the ten on-off valves 12a to 12j, and are supplied with a control signal having a logical value "1" to turn them on. The electromagnetic solenoid connected to the driving transistor is excited, and the control signal of the logical value "0" is supplied to hold the OFF state. The electromagnetic solenoid connected to the driving transistor holds the non-excited state.

In the normal state, the microcomputer 21 has a high spring constant during high-speed traveling, for example, based on a vehicle speed, a vehicle height, and a road surface input according to a main program (not shown) stored in advance in the ROM of the storage device. The vehicle height control process during general running is executed to secure steering stability and reduce the spring constant during low-speed running to improve riding comfort.

Then, the microcomputer 21 executes the vehicle height control process at the time of general traveling, and together with this, it is stored in the ROM of the storage device in advance as shown in FIG. 4, for example, 100 msec.
The vehicle height adjustment processing according to the present invention is executed according to the timer interrupt processing program executed each time.

That is, first, in step, the vehicle speed detection signal DV of the vehicle speed detector 15 and the vehicle height detection signal DH of the vehicle height detector 16 are read, the vehicle speed V and the vehicle height H are calculated based on these, and the vehicle speed detection value V is calculated. And the vehicle height detection value H is temporarily stored in a predetermined storage area of the storage device.

Next, the process proceeds to step and it is determined whether or not the vehicle is stopped based on the vehicle speed detection value V read in the step. Here, when V = 0 when the vehicle is stopped, the process proceeds to step.

In this step, it is determined whether or not the content of the parking brake control flag provided in the storage device in advance has the logical value "1". The determination in this case is to check whether or not the parking brake control was performed after the vehicle was stopped, and when the foot brake or the like was turned on / off again after the vehicle was stopped, the new vehicle height was changed based on the change. This is to prevent a malfunction in which the target vehicle height is set. Here, after stopping,
If the parking brake control is not yet performed, the process proceeds to step.

In this step, the parking brake detection signal DS of the parking brake state detector 18 is read and temporarily stored in a predetermined storage area of the storage device.

Next, the process proceeds to step and it is determined whether or not the parking brake is being braked, based on the parking brake detection signal DS read in the step. Here, when the parking brake is being braked, the process proceeds to step.

In this step, the foot brake detection signal DF of the foot brake state detector 17 is read and temporarily stored in a predetermined storage area of the storage device.

Next, the process proceeds to step, and it is determined whether or not the foot brake is being braked based on the foot brake detection signal DF read in the step. If the foot brake is not being braked, the process proceeds to step.

In this step, it is determined whether or not the content of the foot brake control flag provided in the storage device in advance has a logical value "1". The determination in this case is to check whether the foot brake control has been performed after the vehicle has stopped. In the initial state of the foot brake control flag, for example, the foot brake is reset to the logical value "0", and the foot brake control is performed. Set to logical "1" when control is performed. When the foot brake control flag is set to the logical value "1", the operation shifts to step.

In this step, the foot brake control flag is reset to the logical value "0". Then, the process proceeds to step to read the open / closed state of the door or the trunk, and in step, it is determined whether the door or the trunk remains closed. If the door or trunk continues to be closed, the process proceeds to step and the logical value "1" is set in the parking brake control flag. Then, the process proceeds to step, where a preset value T ₀ set in the timer provided in the storage device is set, whereby the interrupt processing is terminated and the main program is restored. The predetermined value T _{0 in} this case is a value corresponding to the time required until the vehicle height fluctuation caused by the operation of the foot brake and the parking brake is subsided, and the vehicle speed, the vehicle body load, etc. are taken into consideration. And set it appropriately. However, if it is determined in step that the door or trunk has been opened even once, the process proceeds to step, and the vehicle height value H ₃ at the time when the door or trunk is opened is read as the target vehicle height H ₀ .

When it is determined that the vehicle is not stopped at the step, the process proceeds to step and it is determined whether the logical value of the parking brake control flag is "1". If the determination result is the logical value "1", the process proceeds to step, the parking brake control flag is reset to the logical value "0", and then the target vehicle height corresponding to the traveling state is determined in the step. Set H ₀ . After that, the interrupt process is terminated and the process returns to the main program. On the other hand, if the content of the parking brake control flag is not the logical value "1" at the step, the interrupt process is ended and the process returns to the main program.

Furthermore, when the parking brake is controlled after the vehicle is stopped at the step, it is determined whether the timer set at the step has timed up (T ≧ T ₀ ) when the parking brake is controlled. . The determination in this case is made in order to set the target vehicle height to the vehicle height when the vehicle height fluctuation caused by the operation of the foot brake and the parking brake has subsided, and whether the timer content is 0 or not. It is executed by seeing. Here, when the timer is in the time-up state, the process shifts to step.

In this step, the vehicle height detection signal DH of the vehicle height detector 16 is
Is read to calculate the current vehicle height value H ₂ , the contents of the target vehicle height value storage area are rewritten, and the target vehicle height H ₀ is read with the current vehicle height H ₂ . Accordingly, the target vehicle height H ₀ when the timer is deactivated and Taimuatsupu, that is, vehicle height of H ₂ after the vehicle swing back was One Osama is set.

On the other hand, when it is determined in the step that the timer is not in the time-up state, the interrupt process is ended and the process returns to the main program.

Further, when it is determined that the parking brake is not in operation in the step, and when the content of the foot brake control flag is not the logical value "1" in the step, the interruption processing is ended and the main program is ended. Return to.

Further, when it is determined in the step that the foot brake is being braked, the step moves to step and it is determined whether or not the content of the foot brake control flag is the logical value "1". Here, when the foot brake control flag is set to the logical value "1", the interrupt process is ended and the process returns to the main program. However, when the foot brake control flag is set to the logical value "0", the process shifts to step, the logical value "1" is set to the foot brake control flag, and then the main program is restored.

 Next, the operation will be described.

It is assumed that the vehicle is now traveling on a flat road, as shown in FIG. 6 (a), and has changed to traveling on a slope, as shown in FIG. 6 (b). When the interrupt processing program is executed, first, in step, the vehicle speed detector
The vehicle speed detection signal DV of 15 is read, and the vehicle speed value V is calculated based on this. At this time, since the vehicle is in a running state,
Since V ≠ 0 and it is determined that the vehicle is not stopped, the process proceeds to step, the parking brake control flag is reset to a logical value "0", and then the target vehicle height H ₀ is set according to the traveling state in step. To do. This completes the interrupt process and returns to the main program.

If the vehicle is stopped by depressing the foot brake pedal in the middle of this slope, it is determined that V = 0 and the vehicle is stopped at the step. Therefore, the operation proceeds to step and the contents of the parking brake control flag are logical. It is determined whether the value is "1".

At this time, since the logical value "0" is set in the parking brake control flag in the initial setting, it is determined that the content of the parking brake control flag is the logical value "0" in step. Therefore, the process goes to step to read the parking brake detection signal DS of the parking brake state detector 18, and then the process goes to step to determine whether or not the parking brake is being braked.

At this time, assuming that the parking brake is in the off state where it is not yet actuated as in the initial state shown in FIG. 5 (a), the interrupt process is ended and the process returns to the main program.

Next, an interrupt process is executed, and if the parking brake is braked by pulling the parking brake lever at this time (ON state), it is determined that the parking brake is being braked in step, and therefore the process shifts to step. In this step, the foot brake detection signal DF of the foot brake state detector 17 is read, and then the step shifts to a step to determine whether or not the foot brake is being braked.

At this time, as in the initial state shown in FIG. 5 (b), when the foot brake is braking while the brake pedal is still depressed from the beginning when the vehicle is stopped,
After shifting to step, it is determined whether or not the content of the foot brake control flag provided in the storage device is the logical value "1". In this case, since the foot brake control flag is set to the logical value "0" in the initial setting, the contents of the foot brake control flag are determined to be the logical value "0" in step. Therefore, the process shifts to the step, the logical value "1" is set in the foot brake control flag, the interrupt process is ended by this, and the process returns to the main program.

As described above, when both the foot brake and the parking brake are being braked, all the front wheels and the rear wheels are similarly braked. Therefore, even when the vehicle is stopped midway on the slope, the floor surface of the vehicle body is not sloped. Is almost parallel to the inclined surface of.

From this state, further interrupt processing is executed. At this time,
When the foot pedal is released and the foot brake is changed to the inoperative state, the step is processed and it is determined that the foot brake is not being braked.Therefore, the step shifts to the foot brake control flag. It is determined whether the content of is a logical value "1".

In this way, when the brakes of the foot brakes are released and the brakes are displaced to the braking state only by the parking brakes, the parking brakes generally target only the rear wheels. Therefore, as shown in FIG. Since the load acts rearward, the posture of the vehicle body changes to rearward and downward.

In the above step, since the foot brake control flag is set to the logical value "1" by the processing of the step, the step shifts to the step and the foot brake control flag logical value is reset to "0". Then, at step, it is judged whether the door or the trunk is still closed.If it is judged that the door or the trunk is opened, it is presumed that the occupant gets on or off and the luggage is unloaded. , The vehicle height before these operations are performed, that is, the vehicle height H ₃ when the door or the trunk is opened is replaced with the target vehicle height H ₀ . When it is determined that the door or the trunk is closed at the step, it is assumed that the occupant does not get on and off, and the process proceeds to step, and the logical value "1" is set to the parking brake control step. Next, at step t1, as shown in FIG. 5 (c), a timer provided in the memory device is set to a predetermined value T ₀ at the time point t1, and the interrupt process is ended and the main program is restored. To do.

When the interrupt process is executed again, at the step, since the logical value "1" is set in the parking brake control flag by the process of the step, it is determined that the parking brake control flag is in the logical value "1". Therefore, the process shifts to step and it is determined whether or not the timer has timed out.

At this time, when the predetermined time T ₀ has not elapsed since the timer was set in the step, the interrupt processing is ended and the main program is restored.

On the other hand, as shown in FIG. 5 (d), when the vehicle height fluctuation has subsided after the lapse of a predetermined time T ₀ from the timer set, it is determined that T ≧ T ₀ in step, and therefore, the vehicle shifts to step and the vehicle height is changed. Read the new vehicle height detection signal DH of the detector 16,
This calculates the current vehicle height H _2, which the rewritable contents of the target vehicle height value storage area, replaced the target vehicle height H ₀ for the current actual vehicle height H _2.

Therefore, when the vehicle height increases due to the release of the foot brake, the target vehicle height is corrected to the higher side as the actual vehicle height changes, and therefore the vehicle height adjustment based on the vehicle height variation is not executed.

From this state, as shown in FIG. 6 (c), when the vehicle climbs up a slope and is displaced to a flat traveling, the target vehicle height is newly read due to the vehicle variation. Therefore, even when the vehicle height changes based on the braking states of the foot brake and the parking brake when the vehicle is stopped on a slope, only the target vehicle height value H ₀ is read and the vehicle height adjustment is not executed. Then, the vehicle height adjustment is executed based on the vehicle height fluctuation caused by the road surface unevenness or the like that occurs thereafter.

Thus, in this invention, when the vehicle changes its posture when the vehicle stops on a slope due to the difference between the wheel braked by the foot brake operation and the wheel braked by the parking brake operation, Since the vehicle height adjustment is not actually executed but only the target vehicle height is read based on the vehicle height variation, it is possible to eliminate the vehicle height adjustment when the vehicle is stopped, which is performed in the prior art. Therefore, it is possible to prevent the occupant from feeling uncomfortable or anxious based on the vehicle height variation when adjusting the vehicle height. Moreover, since the vehicle height adjustment that does not make much sense due to the difference in the brake operation is not performed, the frequency of operation of the vehicle height adjustment actuator and vehicle height adjusting means is reduced, and the durability of these is eased.
These costs can be reduced.

Although the microcomputer 20 is used as the controller 20 in the above embodiment, the controller 20 is not limited to this, and may have an electronic circuit configuration such as a comparison circuit, a logic circuit, and a timer circuit. Further, although the vehicle height adjustment and the spring constant adjustment are performed by using air, it goes without saying that the vehicle height adjusting actuator may be configured by a vehicle height adjusting device using a fluid or liquid other than air. Furthermore, as a control method, the timer shown in the step of FIG. 4 is not essential, and if the logical value "1" is set in the parking brake control flag, an immediate vehicle height control stop command is output. good. Further, the command output can be canceled by detecting that the ignition key is turned from the ON state to the OFF state.

(Effect of the Invention) As described above, according to the vehicle height adjusting device of the present invention, the vehicle speed detector, the vehicle height detector, the foot brake state detector, the parking brake state detector, and the door / trunk state detector. Based on each detection signal of, the vehicle height adjustment actuator is always output a drive command for vehicle height adjustment to the vehicle height adjustment means, and the vehicle is in a stopped state with the door or trunk closed, and the foot brake and parking brake are When only the foot brake is deactivated from the state where and are operating together, the device is provided with the control means that outputs the command to the vehicle height adjusting means to prohibit the vehicle height adjustment by the vehicle height adjusting actuator. While maintaining steering stability and comfortable riding comfort by adjusting the vehicle height, prohibiting vehicle height adjustment to prevent deterioration of ride comfort and anxiety when the vehicle is stopped on a slope with changes in vehicle height At the same time, it is possible to improve the durability and reliability of the vehicle height adjusting actuator and the vehicle height adjusting means.

[Brief description of drawings]

FIG. 1 is a block diagram showing the basic configuration of the present invention, FIG. 2 is a system explanatory view showing an embodiment of the present invention, FIG. 3 is a block diagram showing the same embodiment of the present invention, and FIG. A flow chart showing an example of the processing procedure of the control device according to the present invention, FIG. 5 is a signal waveform diagram for explaining the operation of the present invention, FIG. 6 is a diagram for explaining the present invention, and FIG. It is a figure for demonstrating a technique. 1a to 1d ... Suspension device, 2 ... Shock absorber, 3 ... Rubber-like elastic body, 4 ... Air chamber (vehicle height adjusting actuator), 6 ... Body, 7 ... Axle, 8 ... Communication hole , 9 ... Complexer, 10 ... Main tank, 11a-1
1d ... Sub tank, 12a-12j ... Open / close valve, 15 ... Vehicle speed detector, 16 ... Vehicle height detector, 17 ... Foot brake condition detector, 18 ... Parking brake condition detector, 19 ... Door・ Trunk condition detector, 20 ... Controller, 21 ... Microcomputer, 22a-22j ... Drive transistor,
23a-23j ... Electromagnetic solenoid

 ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Kazunobu Kawabata 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (56) References JP-A-58-49503 (JP, A) JP-A-58- 53508 (JP, A) Actual development Sho 58-126509 (JP, U)

Claims (1)

[Scope of utility model registration request] 1. A vehicle height adjusting actuator interposed between a vehicle body and a wheel so that the vehicle height can be adjusted, a vehicle height adjusting means for driving the vehicle height adjusting actuator to adjust the vehicle height, and a vehicle height adjusting means for adjusting the vehicle speed. The vehicle speed detector that outputs the detection signal, the vehicle height detector that outputs the detection signal according to the vehicle height, and the detection signal according to the operating state of the foot brake that applies the braking force to all the front and rear four wheels of the vehicle Foot brake condition detector that outputs a signal, a parking brake condition detector that outputs a detection signal according to the operating condition of the parking brake that applies braking force to only one of the front and rear wheels of the vehicle, and the opening or closing of the vehicle door or trunk. A door / trunk condition detector that outputs a detection signal according to the condition, and each of the vehicle speed detector, vehicle height detector, foot brake condition detector, parking brake condition detector, and door / trunk condition detector. Based on the output signal, a drive command for adjusting the vehicle height by the vehicle height adjusting actuator is always output to the vehicle height adjusting means, and the vehicle is in a stopped state with the door or trunk closed, and the foot brake and the parking brake. When only the foot brake is deactivated from the state in which both and are operating, the control means outputs a command to the vehicle height adjusting means to prohibit the vehicle height adjustment by the vehicle height adjusting actuator. Characteristic vehicle height adjustment device.